The door opened and Agnes stood before them. Her face was pale and anxious but her mouth was set in a hard line as she looked them up and down.

"There's but three of you," she said quietly. "Where are those little ones?"

Peter gulped. "They're all right, Agnes; they're here. They've just gone upstairs to wash."

Agnes relaxed a little. "And those boys?" she said suddenly.

Penny tried this time.

"We're very, very sorry, Agnes dear. I know we're wrong and it's all my fault. I'm responsible and I really know it was rude and thoughtless of us to be so late. We've been out exploring and didn't know exactly what the time was... Please forgive us?"

"Where are those boys?" the housekeeper repeated.

"I don't think they'll be long," Penny said, a little too brightly. "We haven't been with them for some time but we know they'll soon turn up... Don't worry about our supper, please Agnes... I mean, we'll get it and clear it away afterwards."

Before Agnes could reply the door opened and the twins entered. They were quick to sense the atmosphere, and while Mary rushed over to Agnes and flung her arms round her, Dickie looked soberly at Peter and shook his head.

"It's so lovely to be back, Agnes darling," Mary said. "Please don't be too cross with us. We've had the loveliest adventures and now we're cold and hungry - only just now I said to Dickie that the best thing about going out and having fun is coming back home and being looked after by Agnes. Didn't I, twin?"

"Yes, you did!... Did you happen to notice when Mr Cantor went out, Agnes?"

The housekeeper never could resist the twins.

"Ah well," she said, "I know there's not one of you means any harm but you mustn't worry me like this. Now be sitting down as quick as you can and enjoy some nice hot soup... Mr Cantor, did you say, Dickie?... He dashed out in a great hurry about an hour gone, shouting to me from the front door-step that he didn't know when he would be back. I must say I've been having a very upsetting evening."

The hot supper was very welcome but Peter nearly choked once when she looked at the three empty places and then noticed Penny doing the same. It was so utterly unlike David not to turn up when he had promised that she was now really frightened.

But there was no chance to talk her worries over for Agnes came in and shut the door firmly behind her.

"Now I'm having no more nonsense," she began, "unless those boys are in this house by nine o'clock - and that's just under the hour - I'm going to the police station and you're all coming with me. This is beyond a joke for me, I can tell you, and I should, by rights, be ringing up your parents this very minute."